Adjustable die



Jan. 5, 1954 Filed Feb. 23, 1951 L. W. ANDREWS ADJUSTABLE DIE 4Sheets-Sheet 1 Jan. 5, 1954 L. w. ANDREWS 2,664,996

ADJUSTABLE DIE Filed Feb. 23, 1951 4 Sheets-Sheet 2 Jan. 5, 1954 L, w.ANDREWS ADJUSTABLE DIE Filed Feb. 25, 1951 4 Sheets-Sheet 3 Jan. 5, 1954w. ANDREWS 2,664,996

ADJUSTABLE DIE Filed Feb. 25, 1951 4 Sheets-Sheet 4 Patented Jan. 5,1954 UNITED STATES PATENT OFFICE ADJUSTABLE DIE Application February 23,1951, Serial N 0. 212,369

Glaims priority, application Great Britain February 28, 1950 This.invention relates to. an improved adjustablev die suitable, for example,for drawing, form:

3 Claims. (Cl. 205-26) tungsten carbide, when assembled and clampedtogether, can be used for the purpose of drawing bars of polygonalsections. Clamping screws, together with adjusting screws, are used toposition the blocks in their proper assembly and, by adjustment,todetermine the shapeand size of the die-hole thus produced at thecentre of thea-ssembly. The nature of the components of the sets and themethod of assembly and adjustment have been such, however, that settingto a predetermined size of hole is complicated and that the drawingrange of any single complete assembly or dieis limited. Furthermore, anysingle die assembly is relatively cumbersome and easily damaged bymis-handling or by bad setting, and, owing to the many screws employed,tends to lack rigidity.

An adjustable die according to the invention comprises (1) a set of dieblocks shaped to nest together complementarily with slidable adjustmentin assembly to form a die-hole having thesamenumber of sides as thenumber of die blocks in theset, the said slidable' adjustment enablingthe assembly to be arranged to give various dimensions of the diehole;(2) a holder having an apertured base for supporting the dieblocks andcomprising an inner retaining wall; (3) a set of backing blocks snuglyinterposed between the said retaining wall and the die blocks, thebacking blocks being formed to match a particular arrangement of theassembly of die blocks; and (4') means operable to compress the backingblocks between the said retaining wall and the assembleddie blocks,andthus to clamp the latter firmly. in position.

A cover plate, surmounting the Whole assembly of die. blocks and backingblocks and detachably secured to the holder, may act as a furtherclamping means for holding the assembly together.

Each die block may be formed of or faced with hard metal. cemented.tungsten carbide or othermaterial" suitable for the purpose of the die.The other. parts are made,.f.or example, of steel. The

die block is preferably ground and lapped so that the die face, that isthe face which constitutes a walllsurfaceof the die-hole, has a convexcylindrical surface, whereby the die-hole is formed with a throat. Asecond'face of each die-hole, which is inclined at the required angle tothe die face,

' isaccordingly-provided with-acorresponding concavecylindrical surfaceto nestslidably on the convex die face of its adjacent die block. Theouter surface, or third face, of each die block may be a plane surface,or two or more plane surf-aces inclined to one another, according to thenature of the engagement thereon of the corresponding backing blockwhich isinterposed betweenthe d-ie block and the retaining wall of theholder. Different sets of die blocksr'may be provided for alternativeuse according to. the form, asdistinct from dimensions, of the di'eho1'esection required. It will be understood that. one set of backing blockscorresponds to a particular setting of the assembly of a set of dieblocks and therefore to a die-hole of predetermined dimensions producedwith such assembly. Accordingly the adjustable die outfit will normallycomprisea-number of sets of backing blocks corresponding respectively tothe different dimensions of die-holes required to be produced from oneset of die block-s.-

Advantages of the present invention are that a single set of die blocksmay be used, with the appropriate sets of backing blocks, throughoutsubstantially the full range of the adjustment of the assembly of dieblocks to: dimensions ofdiehole; and that the assembly is-relativelysimple to handle, to adjust and to clampto rigidity.

An embodiment of the invention is illustrated in the accompanying,drawings of which:

Figure 1 is a plan view of a set of die blocks and a corresponding setof backing block's, both sets of blocks. being unassembled;

Figure 2 is a plan view showing; a slight, modification of the backingbl'ocksof Figure 1, the-die blocks being the same.

Figure 3 is a plan view of the blocks'ofFigu're 1 assembled andmountedin a holder.

Figure 4.is a section on the line 6-4 of Figure 3 and including a coverplate.

Figure 5 is a plan view of the. blocks of Figure 2 assembled and mountedin thesame holder. as that shown in. Figure 3.

Figures 1 and 2sl1ovv' identical sets-of six .die blocks, all marked D1,adaptedfor assembly to produce die-holes of hexagonal section. Thebacking blocks in.Figure: 1, all marked B1, are adapted to match anassembly of'the-die blocks when a relatively small die-hole of regularhexagonal section isformed-l "The backing blocks in Figure 2, all markedB8, are. adapted to match an assembly of the die blocks when.arelatively large die-hole of regular hexagonal section is formed. Theessentialdifference between the blocks B7 and the blocksBB is thattheformer have. a front face witha recess which: provides the face withtwo staggered. parallel portions 35,

36, whilst" the latter'h'ave a; front; face: with ;a projection whichprovides it wlth two staggered parallel portions 31, 38. In each casethe backing blocks are of substantially rectangular form, the back faces39 being parallel with the front faces.

The die blocks D1 used in the embodiment shown in Figures 1-3, have aconvex side In for producing one wall of the die-hole and a matchingconcave side I l for slidably fitting the convex side 10 of an adjacentdie block, but the back faces l2, I3 are respectively at right angles tothe sides ll, l0. This ensures that in assembly the back face 12 of oneblock will be in parallel relationship with the back face l3 of anadjacent block.

Referring now to Figure 3 in which the blocks of Figure 1 are shownassembled, the holder of the adjustable die comprises a body 20 with acentral aperture 2| in its base. The body is formed integrally with apart 40, which provides an inner wall confining the space within whichthe die blocks and backing blocks are assembled to make a die-hole 3|.It will be appreciated that the part it may be formed as a separateelement fitted into a recess in the body 26 and keyed against rotationas in the previous em bodiment. It will also be appreciated that thebase of the body 20 may be recessed to accommodate an interchangeablesupporting plate, with a relatively large or relatively small centralaperture.

The inner wall 4| of the part 40 is of hexagonal form with slots 42 atits corners. The back faces 29 cf the backing blocks B1 are in fiushcontact with the respective faces of the inner wall 41 whilst the frontfaces 35, 36 are respectively in flush contact with the back face i3 ofone die block D1 and the back face l2 of an adjacent die block Dl.

Penetrating radially through the body 20 and the part 40 thereof is aclamping screw 28 bearing on the back face of one backing block. Whenthis is tightened the said backing block is pressed towards the dieblock assembly whereby the entire assemblies of die blocks and backingblocks are clamped in a state of compression. If desired, the clampingscrew 28, instead of bearing directly on a backing block, may bear on aplate fitted into a recess in the wall 4|.

Figure 4 shows, fitted on the body 20 of the holder, a cover plate 32secured by bolts 33. It will be noted that the cover plate has a bossportion 43 tting in a recess in the body 20 to bear on the die assembly.

The only difference between Figure and Figure 3 is that Figure 5 showsassembled in the holder the die blocks D1 and backing blocks B8 ofFigure 2, such assembly making a larger diehole 3|. In this case theback face 12 of a die block lies back nearer to the wall 4! than theback face l3 of the adjacent die block and therefore backing blocks B8having projecting portions 31 are required.

I claim:

1. An adjustable die comprising a set of die blocks slidably assembledcomplementarily to form a die-hole of polygonal section, each die blockproviding one side of the polygonal section and having two back faces atan angle to one another such that in the assembly of die blocks eachpair of adjacent die blocks presents back faces in staggered parallelrelationship; a holder formed to provide a recess having an aperturedbase for supporting the die blocks and having a wall with faces formingsubstantially the same polygonal shape, on an enlarged scale, as thesection of said die-hole; and a set of backing blocks in said recesshaving back faces in flush contact with the respective faces of saidwall and having front faces formed with parallel portions staggeredcorrespondingly to the staggerin of the back faces of adjacent dieblocks and engaging the said back faces.

2. An adjustable die comprising a set of die blocks shaped to nesttogether complementarily with slidable adjustment in assembly to form adie-hole having the same number of sides as the number of die blocks inthe set, the said slidable adjustment enabling the assembly to bearranged to give various dimensions of the die hole, each die blockhaving two back faces at an angle to one another such that in theassembly of die blocks each pair of adjustable die blocks presents backfaces in staggered parallel relationship, a holder formed to provide arecess having an apertured base for supporting the die blocks inassembly and having a wall to surround the assembly, the said wallhaving faces forming substantially the same polygonal shape, on anenlarged scale, as the section of said die hole and at least on set ofbacking blocks adapted to be supported by said base and to be interposedin spaced relationship between the assembly of the die blocks and saidwall, a front face of each backing block being formed with parallelportions staggered correspondingly to the said staggered parallelrelationship of the back faces presented by a pair of adjacent dieblocks.

3. An adjustable die comprising a set of die blocks shaped nest togethercomplementarily with slidable adjustment in assembly to form a die-holehaving the same number of sides as the number of die blocks in the set,the said slidable adjustment enabling the assembly to be arranged togive various dimensions of the die hole, each die block having two backfaces at an angle to one another such that in the assembly of die blockseach pair of adjustable die blocks presents back faces in staggeredparallel relationship, a holder formed to provide a recess having anapertured base for supporting the die blocks in assembly and having awall to surround the assembly, the said wall having faces formingsubstantially the same polygonal shape, on an enlarged scale, as thesection of said die, and at least one set of backing blocks adapted tobe supported by said base and to be interposed in spaced relationshipbetween the assembly of the die blocks and said wall, a front face ofeach backing block being formed with parallel portions staggeredcorrespondingly to the said staggered parallel relationship of the backfaces presented by a pair of adjacent die blocks; and means forcompressing the backing blocks between said wall and said assembly ofdie blocks.

LEONARD VTILFRED ANDREWS.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 546,202 Thackray Sept. 10, 1895 567,606 McCool et al Sept. 15,1896 686,365 Thackray Nov. 12, 1901 1,258,874 Clayton Mar. 12, 19181,922,770 Kornbrath Aug. 15, 1933 2,161,689 Richardson Dec. 7, 1937FOREIGN PATENTS Number Country Date 493,038 Great Britain Sept. 30, 1938578,506 Great Britain July 1, 1946

